Why I lost experience orb (level down) upon being hit?

didn't die, I just found myself down leveled quite a lot (from 43 to 34) upon being hit by the mob, well I wasn't 100% sure if been hit is the reason or could be anything else? it happened several times before I'm always baffled ( I'm on 1.12.2).

Most of the minecraft community as a whole can't even use mods, thus no shaders. Of the Java community, most probably either simply do not prefer to use shaders or don't have enough computer to do so while still playing with the mods they want.

it was running on SEUS renewed 1.0 when this happened, I don't have any other mods, considering this is such a popular mod, I assume some others would have this problem as well?

I can't imagine any shader causing any such issues. Shaders have basically nothing at all to do with this issue. I'm no expert, but I've never heard of such a thing and, to be perfectly honest, have trouble believing levels mysteriously disappearing. Not saying you're lying. Stranger bugs exist. But, this problem doesn't sound logical to me.

It could be that a piece of your armor that you are wearing has mending on it. As i understand it, the enchantment mending uses XP that you get to keep whatever you enchant with it up to full durability, so maybe when you got hit by that mob, your item took some of your XP to fix itself. If you dont then idk im not sure what to say.

It could be that a piece of your armor that you are wearing has mending on it. As i understand it, the enchantment mending uses XP that you get to keep whatever you enchant with it up to full durability, so maybe when you got hit by that mob, your item took some of your XP to fix itself. If you dont then idk im not sure what to say.